\begin{tikzpicture}[>=Stealth]
    \draw [->] (-2.5,0) -- (2.5,0) node[anchor=north] {$x$};
    \draw [->] (0,-2.5) -- (0,2.5) node[anchor=east] {$y$};
    \node at (-0.3,-0.3) {$O$};

    \draw [->] (0.5, 0) arc (0:90:0.5);
    \node at (0.6, 0.6) {$90^\circ$};

    \draw [->] (1.2, 0) arc (0:270:1.2);
    \node at (-1.5, 0.5) {$270^\circ$};
\end{tikzpicture}
